JP3311110B2 - Crosstalk sound control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crosstalk sound control apparatus using active crosstalk sound control in a sound reproduction apparatus for reproducing different sound sources from an adjacent speaker under environmental noise.

[0002]

2. Description of the Related Art In recent years, as a part of passenger service in trains and aircraft, music is provided by speakers with embedded seats, and sound leaking to the surroundings is output from the speakers by using digital signal technology to output control sounds. An active crosstalk control method that silences at a listening position has been proposed.

Hereinafter, a conventional crosstalk sound control device will be described with reference to the drawings.

FIG. 4 is a block diagram of a conventional crosstalk sound control device. In FIG. 4, 1a and 1b are adaptive filters, 2a and 2b are delay units, 3a and 3
b is an adder, 4a and 4c are speakers, 6a and 6b are detectors (microphones), and 7a and 7b are sound sources. Here, it is assumed that the sound sources 7a and 7b generate music signals for simplicity.

The operation of the above-structured crosstalk sound control device will be described below.

[0006] A signal from a sound source 7a is input to an adaptive filter 1a and a delay unit 2a. Similarly, a signal from the sound source 7b is input to the adaptive filter 1b and the delay unit 2b. Next, the output signal of the adaptive filter 1a and the output signal of the delay unit 2b are added in the adder 3b. Similarly, the output signal of the adaptive filter 1b and the output signal of the delay unit 2a are added in the adder 3a.

The outputs of the adders 3a and 3b are reproduced by speakers 4a and 4c, respectively. Here, since the speakers 4a and 4c are close to each other, the crosstalk sound between them is detected by the detectors 6a and 6b. In order to attenuate this crosstalk sound, the adaptive filter 1a adaptively controls the signal from the sound source 7a so that the detection signal detected by the detector 6b is reduced, and thereby the signal from the speaker 4c to the detector 6b is reduced. Crosstalk sound is attenuated. Similarly, the adaptive filter 1b
Adaptively controls the signal from the sound source 7b so that the detection signal detected by the detector 6a becomes small, and thereby the crosstalk sound from the speaker 4a to the detector 6a is attenuated.

Here, the delay units 2a and 2b are connected to a speaker 4a.
And the speaker 4c are close to each other, and the detectors 6a and 6b are also close to each other, so that the adaptive filters 1a and 1b
In order to prevent the adaptive control time from being out of time, the signals of the sound sources 7a and 7b are delayed.

[0009]

However, the problem to be solved by the present invention (FIG. 4)
When the sound emitted from the environmental noise source 9 is larger than the crosstalk sound, for example, the signal detected by the detector 6b includes, in addition to the crosstalk sound from the speaker 4a and the cancellation sound from the speaker 4c, Environmental noise is included. As a result, the adaptive filter 1a is affected by environmental noise unrelated to the music signal from the input sound source 7a, and the adaptive operation is not stable because the coefficient to be obtained does not converge or the coefficient fluctuates. In some cases, the talk sound is not sufficiently attenuated, or on the contrary, noise is added.

[0010] The present invention solves the above-mentioned problems, and stably attenuates crosstalk sounds from different sound sources close to each other even in a noisy environment, so that the listener can hear only the sound he or she wants to hear. It is an object to provide a control device.

[0011]

In order to achieve this object, a crosstalk sound control apparatus according to the present invention comprises: a sound reproduction apparatus for reproducing different sound sources by means of a speaker built in an adjacent chair; A first adaptive filter that adaptively controls the signal of the first sound source, a first delay unit that delays a signal from the first sound source, a second adaptive filter that adaptively controls the signal of the second sound source, A second delay unit for delaying a signal from a second sound source, a first adder for adding the output of the second adaptive filter and the output of the first delay unit, and the first adaptive filter A second adder for adding the output of the second adder, a first speaker for reproducing the output of the first adder, and a second speaker for reproducing the output of the second adder. 2 speakers A first detector for detecting a sound at a listening point of the first chair, a second detector for detecting a sound at a listening point of the second chair, and a third detection for detecting environmental noise. A third delay for delaying the signal from the second detector; and a fourth delay for delaying the signal from the first detector.
, A third adaptive filter that adaptively controls the output of the third detector and outputs the output to the first adaptive filter, and the second adaptive control that controls the output of the third detector. A fourth adaptive filter that outputs the output of the third adaptive filter, a third adder that adds the output of the third delay device and the output of the third adaptive filter, an output of the fourth delay device, A fourth adder for adding the output of the fourth adaptive filter, and an environment from the output signal of the second detector by the third adaptive filter based on the output of the third detector. Generating a signal for canceling the noise signal component;
The first adaptive filter is adapted to attenuate the crosstalk sound transmitted from the second speaker without being affected by environmental noise, and based on the output of the third detector. A signal for canceling an environmental noise signal component from an output signal of the detector is controlled so that the second adaptive filter attenuates a crosstalk sound transmitted from the first speaker without being affected by environmental noise. It is characterized by being performed.

[0012]

According to the present invention, a signal for canceling the environmental noise signal component is generated by the third adaptive filter based on the output of the third detector and added to the output of the second detector. The environmental noise signal component is removed by the
Can be adaptively controlled. Thus, the crosstalk sound of the first sound source reproduced from the first speaker can be stably attenuated even under environmental noise.

Further, a signal for canceling the environmental noise signal component is generated by a fourth adaptive filter based on the output of the third detector, and the signal is added to the output of the first detector to thereby obtain the environmental noise signal component. , And the second adaptive filter can be adaptively controlled stably with only the music signal component of the crosstalk sound.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a crosstalk sound control apparatus according to a first embodiment of the present invention. In FIG. 1, 1a to 1d are adaptive filters, 2a to 2d are delay devices, 3a to 3d are adders, 4a
And 4c are speakers, 6a to 6c are detectors (microphones), 7a and 7b are sound sources, and 9 is an environmental noise source. Here, it is assumed that the sound sources 7a and 7b generate music signals for simplicity.

The operation of the crosstalk sound control device configured as described above will be described below.

The music signal output from the sound source 7a is input to the adaptive filter 1a and the delay 2a. Similarly, the music signal output from the sound source 7b is input to the adaptive filter 1b and the delay unit 2b. Next, the output signal of the adaptive filter 1a and the output signal of the delay unit 2b are added in the adder 3b and reproduced by the speaker 4c. Similarly, the output signal of the adaptive filter 1b and the output signal of the delay unit 2a are added in the adder 3a and reproduced by the speaker 4a. Here speaker 4
Since a and 4c are close to each other, their crosstalk noises are detected by the detectors 6a and 6b. However, in a noise environment, the crosstalk noise is further added to the environmental noise source 9 uncorrelated with the sound sources 7a and 7b.
Is superimposed, and the superimposed signal is transmitted to the delay unit 2
c, 2d. Further, a detector 6c provided to detect a noise signal from the environmental noise source 9 detects noise from the environmental noise source 9.

The noise signal detected by the detector 6c is convolved with the approximated transfer function from the detector 6c to the detector 6b by the adaptive filter 1c and output to the adder 3c. The output of the delay unit 2c and the output of the adaptive filter 1c are added by an adder 3c, and the added signal is used as a control signal for the adaptive filter 1c and the adaptive filter 1a. Adaptive filter 1
c performs adaptive control so that the control signal is minimized. As a result, the output from the adder 3c is only a crosstalk sound.

Similarly, the noise signal detected by the detector 6c is applied to the detector 6c by the adaptive filter 1d.
Are convolved with the approximated transfer function from the detector 6a to the detector 6a and output to the adder 3d. The output of the delay unit 2d and the output of the adaptive filter 1d are added by an adder 3d, and the added signal is used as a control signal for the adaptive filter 1d and the adaptive filter 1b. The adaptive filter 1d performs adaptive control so that the control signal is minimized. As a result, the output from the adder 3d is only a crosstalk sound.

The adaptive filter 1a includes a detector 6b
, The signal from the sound source 7a is adaptively controlled so as to reduce the detection signal at, so that the crosstalk sound from the speaker 4a to the detector 6b is attenuated. Similarly, the adaptive filter 1b adaptively controls the signal from the sound source 7b so as to reduce the detection signal at the detector 6a, whereby the crosstalk sound from the speaker 4c to the detector 6a is attenuated. Here, the delay units 2a and 2b are arranged such that the speakers 4a and 4c
a and the detector 6b are also close, so the adaptive filter 1
The signals of the sound sources 7a and 7b are delayed in order to prevent the time for adaptive control by a and 1b from being out of time.
It consists of a digital filter. In addition, the delay units 2c,
When the detector 6a or 6b and the detector 6c are close to each other, the detector 2d is used to prevent the adaptive control by the adaptive filters 1c and 1d from being out of time.
The crosstalk sound detected at a and 6b is delayed. Here, it is assumed that the crosstalk sound interferes with the adaptive control of the environmental noise, but there is no problem since the crosstalk sound reproduced from the speakers 4a and 4c is sufficiently smaller than the environmental noise.

As described above, according to the present embodiment, the adaptive filters 1c and 1d generate signals for canceling the environmental noise from the environmental noise source 9, and the adders 3c and 3d generate the signals from the detectors 6a and 6b. By the addition, the components of the control signals of the adaptive filters 1a and 1b can be only the crosstalk sound, and the crosstalk sound can be reduced stably.

When the volume difference between the crosstalk sound detected by the detectors 6a and 6b and the environmental noise detected by the detector 6c is small, the crosstalk sound may hinder the adaptive control of the environmental noise. , Adaptive filter 1
The adaptive control of c and 1d is performed when the music signal is not being reproduced, and the adder 3 is started when the reproduction of the music signal is started.
Switching may be performed so that c and 3d are not output to the adaptive filters 1c and 1d.

Hereinafter, a second embodiment of the present invention will be described.

FIG. 2 shows a block diagram of the crosstalk sound control device when the signal output from the sound source is a stereo music signal. In FIG. 2, 1a
1d is an adaptive filter, 2a-2f are delay units,
3a to 3d are adders, 4a to 4d are speakers, 6a to 6
c is a detector, 7a and 7b are stereo sound sources, and 9 is an environmental noise source.

The operation of the crosstalk sound control device configured as described above will be described below.

As for the music signal from the sound source 7a, the R channel signal is input to the adaptive filter 1a and the delay unit 2a, and the L channel signal is input to the delay unit 2e. Similarly, as for the music signal from the sound source 7b, the L channel signal is input to the adaptive filter 1b and the delay unit 2b, and the R channel signal is input to the delay unit 2f.

Next, the output signal of the adaptive filter 1a and the output signal of the delay unit 2b are added in an adder 3b and reproduced by a speaker 4c. Similarly, the output signal of the adaptive filter 1b and the output signal of the delay unit 2a are added in the adder 3a and reproduced by the speaker 4a. The output signal of the delay unit 2e is reproduced by the speaker 4b, and the output signal of the delay unit 2f is reproduced by the speaker 4d. Here, since the speakers 4a and 4c are close to each other, the crosstalk sound of each other is detected by the detectors 6a and 6b. However, in a noise environment, the crosstalk sound from the environmental noise source 9 uncorrelated with the sound sources 7a and 7b. Noise is superimposed and delay unit 2
c, 2d.

Here, at the same time, the noise from the environmental noise 9 is detected by the detector 6c. The noise signal detected by the detector 6c is convolved with the approximated transfer function from the detector 6c to the detector 6b by the adaptive filter 1c and output to the adder 3c. The adder 3c adds the output of the delay unit 2c and the output of the adaptive filter 1c to generate a control signal for the adaptive filter 1c and the adaptive filter 1a. The adaptive filter 1c performs adaptive control so that the control signal is minimized, and as a result, the adder 3c
Outputs only a crosstalk sound.

Similarly, the adaptive filter 1d convolves the approximated transfer function from the detector 6c to the detector 6a with the noise signal detected by the detector 6c and outputs it to the adder 3d. The adder 3d adds the output of the delay unit 2d and the output of the adaptive filter 1d to generate a control signal for the adaptive filter 1d and the adaptive filter 1b. The adaptive filter 1d performs adaptive control so that the control signal is minimized. As a result, the output of the adder 3d is only a crosstalk sound.

The adaptive filter 1a includes a detector 6b
, The signal from the sound source 7a is adaptively controlled so as to reduce the detection signal at, so that the crosstalk sound from the speaker 4a to the detector 6b is attenuated. Similarly, the adaptive filter 1b adaptively controls the signal from the sound source 7b so as to reduce the detection signal at the detector 6a, whereby the crosstalk sound from the speaker 4c to the detector 6a is attenuated. Here, the delay devices 2a and 2b are designed to prevent the speakers 4a and 4c from being close to each other and the detectors 6a and 6b from being close to each other, so that the adaptive control by the adaptive filters 1a and 1b cannot be performed in time. To prevent this, the signals of the sound sources 7a and 7b are delayed. In addition, when the detectors 6a or 6b and the detector 6c are close to each other, the delay units 2c and 2d detect noises detected by the detector 6c in order to prevent the adaptive filters 1c and 1d from being out of time. Source 9
The noise signal from is delayed.

Since the sound sources 7a and 7b generate a stereo signal, the delay units 2e and 2f are delayed by the same time as the delay units 2a and 2b so that the localization does not change. Here, it is assumed that the crosstalk sound interferes with the adaptive control of the environmental noise, but there is no problem because the crosstalk sound reproduced from the speakers 4a and 4d is sufficiently smaller than the environmental noise.

FIG. 3 shows a configuration in which the speakers 4a to 4c and the detectors 6a and 6b used in the second embodiment are embedded in chairs 8a and 8b provided adjacent to an automobile, a train, an airplane, or the like. It is the perspective view which showed an example. Note that, in the configuration of the first embodiment shown in FIG. 1, the speakers 4a and 4c and the detectors 6a and 6b can be embedded in adjacent chairs as in FIG.

As described above, according to the present embodiment, a signal for canceling the environmental noise from the environmental noise source 9 is generated by the adaptive filters 1c and 1d, and added to the signals of the detectors 6a and 6b by the adders 3c and 3d. Thereby, the components of the control signals of the adaptive filters 1a and 1b can be made only the crosstalk sound, and the crosstalk sound can be reduced stably.

When the difference between the volume of the crosstalk sound reproduced from the speakers 4a and 4c and the volume of the environmental noise detected by the detector 6c is small, the crosstalk noise may hinder the adaptive control of the environmental noise. The adaptive control of the adaptive filters 1c and 1d is performed when the music signal is not being reproduced, and when the reproduction of the music signal is started, the adder 3 is activated.
Switching may be performed so that c and 3d are not output to the adaptive filters 1c and 1d.

[0035]

As is apparent from the above description, the present invention provides an environmental noise signal component included in the output signal of the second detector by the third adaptive filter based on the output of the third detector. Is generated and added to the output of the second detector to remove the environmental noise signal component, and the first adaptive filter can be adaptively controlled only by the crosstalk sound. Thereby, the first
The crosstalk sound of the first sound source reproduced from the speaker can stably attenuate the noise even when the environmental noise is large.

A signal for canceling an environmental noise signal component contained in an output signal of the first detector is generated by a fourth adaptive filter based on an output of the third detector,
By adding this to the output of the first detector, the environmental noise signal component can be removed, and the second adaptive filter can be adaptively controlled only by the crosstalk sound. As a result, the crosstalk sound of the second sound source reproduced from the second speaker can be attenuated stably even when the environmental noise is large.

Accordingly, the present invention provides a crosstalk sound control device capable of stably attenuating crosstalk sounds from different adjacent sound sources even under a noisy environment, and enabling the listener to hear only the sound he or she wants to hear. Can be done.

[Brief description of the drawings]

FIG. 1 is a block diagram of a crosstalk sound control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a crosstalk sound control device according to a second embodiment of the present invention.

FIG. 3 is a perspective view showing an example of a chair in which a speaker and a detector used in the present invention are embedded.

FIG. 4 is a block diagram showing a conventional crosstalk sound control device.

[Explanation of symbols]

 1a, 1b, 1c, 1d Adaptive filter 2a, 2b, 2c, 2d Delay device 3a, 3b, 3c, 3d Adder 4a, 4b, 4c, 4d Speaker 6a, 6b, 6c Detector 7a, 7b Sound source 8a, 8b Chair 9 Environmental noise sources

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Kenichi Terai 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Yoshio Maekawa 1-6-5 Marunouchi, Chiyoda-ku, Tokyo East Japan Railway Company (72) Inventor Hiroshi Abiko 1-6-5 Marunouchi, Chiyoda-ku, Tokyo East Japan Railway Company (72) Inventor Kazunori Hasebe 1-6-5 Marunouchi, Chiyoda-ku, Tokyo East Japan Railway Company (56) References JP-A-4-194996 (JP, A) (58) Fields investigated (Int. . ^7, DB name) G10K 11/178 H04R 3/00 310 H04S 7/00

Claims (3)

(57) [Claims] 1. A sound reproducing apparatus for reproducing different sound sources by a speaker built in an adjacent chair, a first adaptive filter for adaptively controlling a signal from a first sound source, and a signal from the first sound source. , A second adaptive filter that adaptively controls a signal from a second sound source, a second delay device that delays a signal from the second sound source, and a second delay device that delays a signal from the second sound source. A first adding the output of the adaptive filter and the output of the first delay unit
An adder, a second adder that adds the output of the first adaptive filter and the output of the second delay unit, a first speaker that reproduces the output of the first adder, A second speaker that reproduces the output of the second adder, a first detector that detects sound at a listening point of the first chair, and a second detector that detects sound at a listening point of the second chair. A second detector, a third detector for detecting environmental noise, a third delayer for delaying a signal from the second detector, and a third delayer for delaying a signal from the first detector. 4, a third adaptive filter that adaptively controls the output of the third detector and outputs the output to the first adaptive filter, and the third adaptive filter that adaptively controls the output of the third detector. A fourth adaptive filter for outputting to the second adaptive filter, and the third delay A third adder that adds the output of the third adaptive filter and the output of the third adaptive filter, and a fourth adder that adds the output of the fourth delay unit and the output of the fourth adaptive filter. Generating a signal for canceling an environmental noise signal component from an output signal of the second detector by the third adaptive filter based on an output of the third detector, wherein the first adaptive filter generates an environmental noise signal. And a fourth adaptive filter based on the output of the third detector so as to attenuate the crosstalk sound transmitted from the second speaker without being affected by the output signal of the first detector. And a signal for canceling the environmental noise signal component from the first adaptive filter.
A crosstalk sound control device, which is controlled to attenuate crosstalk sound transmitted from a speaker. 2. A method according to claim 1, wherein the first speaker is attached to the first chair, the second speaker is attached to the second chair, and the first chair and the second chair are adjacent to each other. The crosstalk sound control device according to claim 1, wherein: 3. A first delay device comprising a digital filter for correcting a reproduced sound reproduced from a first speaker, and a second delay device comprising a digital filter for correcting a reproduced sound reproduced from a second speaker. The crosstalk sound control device according to claim 1, wherein the control device is configured by a filter.